A) Field of the Invention
The present invention refers to a system and method for detecting and adjusting the position of a burner during the annealing process of a glass sheet, and, more particularly, to a system and a method to detect and automatically adjust the position of a plurality of burners placed on the borders of a continuous glass sheet during its annealing process.
B) Description of the Related Art
The production of glass sheets is initiated from a source of molten glass in a melting furnace. In such a furnace the smelted glass is conditioned to be drawn and then it flows successively through smelting, refining and conditioning chambers to then be supplied to a vertical drawing machine. When the glass begins to be drawn, it flows vertically through a drawing bar which maintains the width of the glass on a constant basis. Subsequently the glass sheet is vertically transported through a chamber made up by numerous pairs of rolls of the machine itself, just as the PPG process, or it continues on a horizontal form such as is used in the process of floated glass. Once the sheet is drawn, it goes on in a continuous form towards a thermal treatment lehr where the glass sheet gradually cools, also annealing the edges, and once it leaves the lehr, the edges are marked in order to remove the lateral irregular sections, and they are also marked transversally in keeping with the required size of the sheet.
Once the required glass sheets are obtained, the same are unloaded through the use of adequate means towards stackers--thus forming a block of various sheets, which must be stored in warehouses to be shipped at a later date.
One of the main problems of the manufacturing process of glass sheets is located in the annealing area. During the process treatment of the glass sheets, the sheets are horizontally moved on top of a series of rolls of a thermal treating lehr they are heated to a temperature of about 650.degree. C. Later the sheets are gradually cool until all of the thermal stresses which were acquired during the manufacturing process is relieved.
During this annealing step it is very important that the lateral edges of the sheet be annealed with the application of independent heat. -which is achieved by the application of a series of burners. Since the edges are later cut, an incorrect annealing provokes their damage or that certain sections of the sheet crack once said sections are separated from the glass sheet.
However, due to the fact that in the manufacturing process of the glass sheets there are slight variations in the width of the same, the position of the burners must be adjusted transversally and in a continuous form, which is achieved starting through the detection of the edges of said sheet, and this is done in order to prevent an incorrect annealing of the same. To date, the adjustment of the burners over the edges of the glass sheet is carried out or is done in a manual manner, and said adjustment depends on the ability of operators and the frequency of the adjustments carried out.
With the end of eliminating the disadvantages of the related art, the present invention refers to a system and a method for automatic positioning the burners on the glass sheets which is done through a continuous detection of the width of the glass sheet.
By means of this system, a good annealing quality of the glass sheet edges is obtained, thus substantially reducing the production losses of the cutting line. In addition to the latter, it will no longer be necessary to depend on the ability of the operators in order to carry out the continuous adjustments of the position of the burners.
In keeping with the above, the present invention refers to a system and a method for detecting and automatically adjust the position of a plurality of burners in respect to the edges of a glass sheet; said glass sheet being annealed in a thermal treatment lehr, the system comprising: a support structure; a reciprocal structure coupled onto the support structure; at least one burner coupled to the reciprocal structure; sensing elements for sensing the position of the edge of the sheet, which are jointly attached to said burners, in order to adjust the position of said burners based on the position of the sensing elements over the edges of said glass sheet; and control means coupled to the sensing elements, in order to adjust the position of the burners in accordance with the real position of the sensing elements placed on the edge of said glass sheet.